The aim of the proposed predoctoral training program is to provide the biomedical community with highly creative and productive molecular bacteriologists, virologists, and mycologists interested in the pathogenesis of disease. This goal is mandated by the intellectual desires and career aspirations of the program's predoctoral trainees and by the health needs of the nation as specified by various task forces of NIH and CDC. This goal will be achieved by having the students follow a highly visible and defined Pathogenesis Track (core curriculum) set in the established interdepartmental graduate training milieu of the University of Rochester School of Medicine and Dentistry (SMD). This fall, the SMD instituted a new required course in biomedical ethics and responsible conduct of research composed of both formal lectures and case discussions. In addition, we have organized a second new ethics course (required of our trainees) specifically addressing concerns unique to working with highly infectious agents, including agents important to biodefense. The essential core environment will be fostered by: a faculty dedicated to excellence in teaching and research and committed to training in molecular microbial pathogenesis and host defenses;active molecular pathogenesis/host defense research programs of trainees and their sponsors;structured lecture courses accompanied by literature review seminars;unique colloquia focused on various aspects of molecular pathogenesis and taught by expert visiting faculty specifically chosen to augment strengths of the training faculty;seminar courses in various aspects of microbial pathogenesis or immunology;various journal clubs and a catalytic number of trainees. Breadth of training in related fields will be accomplished by providing sufficient time and opportunities in the Pathogenesis track for students to attend clinical microbiology and infectious disease conferences and to rotate through the clinical microbiology laboratories. Research opportunities in a wide variety of relevant problems within the purview of molecular microbial pathogenesis and host defense will be offered to trainees by an experienced, talented, and highly interactive primary training faculty. Over the last six years, we have recruited new junior and senior faculty to strengthen and broaden the existing program in virology, bacteriology, mycology, and host defense. We also have faculty who are studying emerging and re-emerging infections and agents important to biodefense. The University of Rochester and SMD has recently undertaken development of a new strategic plan. One of the four basic research areas to be included is "Defense Against External Threats" which includes in the focus of this training grant. This ensures future additional University support for this program. The overall program is further strengthened by collaborations between both basic and clinical faculty and by strong university financial support. The application is for five years with 7 predoctoral trainees each year, as recommended by the previous study section.